In the case of danger, alarm, fire, smoke formation, threats etc, the presence of clearly visible signs on premises is extremely important, for example for indicating the nearest escape route or the location of fire extinguishing equipment, gas cylinders and emergency stops. According to the colour requirements stipulated by the appropriate authority, such safety signs should have one or more white or black, standardised symbols on a red, green or yellow background.
Some of the existing afterglowing safety signs are used, inter alia, to indicate and display escape routes and emergency exits and to indicate the location of fire extinguishing equipment. However, the afterglowing pigments used do not exist in the colour shades needed to obtain an optimal colour reproduction, in normal printing, both in daylight and, with a coloured afterglow, in the dark. The solution to this problem has so far been to accept that these signs show afterglowing symbols only in the dark, in which case their background colour has been perceived as black. Thus, the colour requirements for these afterglowing safety signs are met only in daylight and in lit spaces since the afterglowing pigments available do not completely fulfil the requirements both in daylight/lit spaces and in the dark.
It is also known from SE 0100615-4 to use afterglowing signs printed with afterglowing pigments, which are coated with a screen print using opaque or transparent ink to provide, for instance, safety signs which fulfil the colour requirements both in daylight/lit spaces and, with a coloured afterglow, in the dark. When taking a close look at these signs, they can produce a disturbing impression owing to the screen print, for instance a striped, checked or dotted visual impression. Signs with a screen print may also give the impression of a slightly different colour shade in relation to standard because of the effect of the screen pattern on the visual impression. Especially in the case of safety signs where standardised colour shades and surfaces are used, it is thus desirable to come as close as possible to a homogeneously coloured impression, and reproduce the colour shades as correctly as possible.